Rochinia cidaris, Lee & Forges & Ng, 2019

Lee, Bee Yan, Forges, Bertrand Richer De & Ng, Peter K. L., 2019, Deep-sea spider crabs of the family Epialtidae MacLeay, 1838, from Papua New Guinea, with a redefinition of Tunepugettia Ng, Komai & Sato, 2017, and descriptions of two new genera (Crustacea: Decapoda: Brachyura: Majoidea), Zootaxa 4619 (1), pp. 1-44 : 15

Rochinia cidaris n. sp.

( Figs. 7 A–C, 9A–D)

Material examined. Holotype: male (19.0 × 11.5 mm) (MNHN-IU-2014-19044), stn CP4448, New Ireland, Papua New Guinea, 02°13’S 150°12’E, 564–743 m, coll. KAVIENG 2014, 1 September 2014.

Diagnosis. Carapace pyriform, covered with short, thin setae, smooth when denuded. Supraorbital eave with pre-orbital spine strong, directed upwards. Postorbital lobe cup-like. Carapace with 9 spines; 2 hepatic spines directed outwards, swollen basally; 1 mesogastric spine; 2 epibranchial granules; cardiac region slightly swollen with 1 cardiac spine; 2 short metabranchial spines; 2 long lateral branchial spines, directed outwards; 1 short posterior spine medially ( Fig. 7A ). Antennal flagellum shorter than pseudorostral spines. Basal antennal article longer than broad, distal angle of article blunt. Buccal frame covered by third maxilliped. Pterygostomial region with 4 granules on outer margin ( Fig. 7B ). Male chelipeds slender; propodus slightly inflated, with outer margin carinate; carpus outer surface with single carinate margin; merus triangular in cross-section; single granule on inner proximal surface. Ambulatory legs slender; P2 longest. Male thoracic sternum with sternites 3 and 4 depressed; sternites 3 and 4 with margin constricted anteriorly, posterior widest. Male pleon with triangular telson and 6 somites free ( Fig. 7B ). G1 straight, slightly constricted on distal third, distal tip with slight rounded angle on upper edge near rounded tip ( Fig. 9 A–D).

Etymology. The term “ cidaris ” is a Latin term for crown, alluding to the spiny anterior half of the carapace of the crab. The name is used as a noun.

Remarks. Rochinia cidaris n. sp. is morphologically similar to R. riversandersoni Alcock, 1895 , from off the Malabar coast, India, but differs in having less distinct carapace spines and possessing strong pre-orbital spines ( Fig. 7A, C ) (versus more distinct carapace spines and weak pre-orbital spines; cf. Alcock & Anderson 1896: pl. 22 figs. 2, 4). Rochinia cidaris n. sp. has nine carapace spines ( Fig. 7A ) (versus 11 carapace spines on R. riversandersoni (cf. Alcock 1895: 203; Alcock & Anderson 1896: pl. 22 figs. 2, 4); and its basal anternnal article has a blunt distal angle ( Fig. 7B ) (versus basal antennal article with sharp distal angle in R. riversandersoni (cf. Alcock 1895: 203; Alcock & Anderson 1896: pl. 22 fig. 2a).

The new species is currently only known from its type locality, New Ireland, Papua New Guinea.

Figures

FIGURE 7. Rochinia cidaris n. sp., holotype, male (19.0 × 11.5 mm) (MNHN-IU-2014-19044), Papua New Guinea. A, overall dorsal view; B, overall ventral view; C, lateral view of carapace.

FIGURE 9. A–D, Rochinia cidaris n. sp., holotype, male (19.0 × 11.5 mm) (MNHN-IU-2014-19044), Papua New Guinea, left G1. A, ventral view; B, ventral view of distal portion; C, dorsal view; D, dorsal view of distal portion. E–H, R. despereaux n. sp., holotype, male (15.2 × 10.1 mm) (MNHN-IU-2011-3878), Papua New Guinea, left G1. E, ventral view; F, ventral view of distal portion; G, dorsal view; H, dorsal view of distal portion..